NASA says that the weather forecast for the next decade is favorable – space weather, that is. Based on a new study, the space agency has announced that the Sun is moving into an 11-year period of minimal sunspot activity, which means that the chances of massive solar flares spewing out radiation that could be a deadly hazard to astronauts and spacecraft are much lower.
One of the greatest dangers to space travel is radiation and one of the biggest sources of radiation is the Sun. Though it may seem like the most constant thing in our daily lives, the Sun is actually a variable star run by a very complex mechanism that scientists still don't fully understand.
What is known is that the Sun goes through 11-year cycles during which solar activity rises and falls. This is marked by increases and decreases in the number of sunspots on the surface, which are areas of intense magnetic storms that are thousands of times more powerful than the Earth's magnetic field.
If there are a large number of spots at a time when the Sun is at its most active, then massive solar flares can happen, such as the one that occurred in August 1972 in between the Apollo 16 and 17 missions. They can pose a real hazard to space travelers or probes operating outside the Earth's atmosphere and protective magnetic field.
However, if the number of spots is small at the maximum point in the cycle, then the Sun remains quiet and solar flares are at a minimum. According to NASA, the next cycle that begins in 2020 will reach its maximum in 2025, but the number of spots may be 30 to 50 percent lower than the previous cycle. That would make it the weakest recorded in the last two centuries.
This means that planners have much more leeway when it comes to scheduling mission like NASA's Artemis, which will see American astronauts returning to the Moon
The new forecast is the work of a team led by Irina Kitiashvili of the Bay Area Environmental Research Institute at NASA's Ames Research Center in Silicon Valley, California. Using data collected since 1976 from the Solar and Heliospheric Observatory and the Solar Dynamics Observatory space missions, the researchers were able to come up with a prediction by directly observing the solar magnetic field rather than simply counting sunspots, which provides only a rough gauge of activity inside the Sun.
Because this is a relatively new approach, there is only data from four complete cycles, but by combining three sources of solar observations with estimates of the Sun's interior activity, the team was able to produce a prediction in 2008 that matched the activity that was observed over the past 11 years.
NASA says that these predictions will not only help to protect astronauts, but also unmanned missions as well as the growing networks of Earth-orbiting satellites on which our civilization is coming to depend on more and more.
Source: NASA
